Universal joint



G- E. DUNN UNIVERSAL JOI NT Jan, 20, 1942.

Filed Aug. 1'7, 1940 2 Sheets-Sheet 1 TOR . ATTORNEY-1 INVEN 62023.9 .2.- In) Jan. 20, 1942-. as. DUNN v 2,270,279

- UNIVERSAL JOINT r Filed Aug. 17, 1940 2 Sheets-Shget 2 ZNVENTOR geaiyw Zr. yak; Y,

, application for patent, Serial No. 238,156,

Patented Jan. 20, 1942 UNIVERSAL JDINT George E. Dunn, Dearborn, Mich-., assignor to I Jnit versal Products Company, Incorporated, Dearborn, Mich, a corporation of Delaware Application August 17,1940, Serial no. 353,016

Claims. (01. 64-17) The invention relates generally to motor vehicles and it has particular relation to improvements in universal joints.

In certain respects the invention constitutes a continuation of that embodied in my-copending November 1, 1938.

In the mentioned copending application for filed patent, a universal joint is disclosed which includes a cross having trunnions and ball members tumable onthe trunnions and a pair of yoke members having sockets for receiving the ball members. In a joint of this character, the ball members can align themselves with respect to the trunnions and roller bearings provided within the balls and around the trunnions. Self alignment bearing contact regardless of torque conditions and thus avoids localized roller bearings engage "inent caused by bending, even though slight, of the trunnions. Full roller bearing contact enables reducing the size of the joint since one factor governing the size of the joint is the capacity of the roller hearings to transmit torque load and if they are subjected to localized bearing engagement, a largerroller bearing unit is required.

vWhile alignment of the trunnions, rollers, and ball members is desirable, itis also'desirable to of the ball members enables obtaining full roller have a strong yoke structurewhich will retain the ball members inplace, which will allow assemblyrapidly and without difficulty. and which is'not expensiveto manufacture. Moreover, it is desirable to have a'yoke-structure which does not undesirably enlarge the joint or increase its weight: In general, a structure such as briefly described above is embodied in the copending application for patent mentioned and the present invention is concerned with improvements, which still further enable reducing the size, weight, and cost of the joint, without sacrificing durability and efllclency.

One object of the invention, therefore, is to provide an improved universal joint'of the gen eral type mentioned, which enables reducing the size and the weight of the joint, and the cost of manufacturing and assembling the parts thereof.

Another object of the invention is to provide an improved joint of the type mentioned which has an improved ball member of such character that the overall size of the joint actually can be reduced and manufacturing operations employed in making the ball members can be simplified.

Another object of the-invention is to provide an improved sealing means'for sealing the space or gap at the inner end of the ball members in order to prevent lubricant from escaping from the bearings and to prevent dirt or other foreign matter from gaining access to the bearings.

Other objects of the invention will become apparent from the following specification, from the drawings relating th'ereto,.and from the claims hereinafter set forth. l

- For a better understanding of the invention referencemay be had to the drawings, wherein:

Figure 1 is an elevational view of a universal joint as constructed according to one form of the invention; V

Fig. 2 is a view similar to Fig. 1 but partly in cross-section so as to illustrate the relation of ball, yoke, trunnion, verse section;

Fig. 3 is a cross-sectionalview-taken substantially along the line 3-3 of Fig. 1;

Fig. 4 is a cross-sectional view taken substantially along the line 4--4 of Fig. 1; t

Fig. 5 is a cross-sectional'view taken substantially along the line 5-5 of Fig. 1; Figs. 6 and 7 are detail views in cross-section illustrating other means for sealing the space between the endof the ball members and the trunnions. Referring to Figs. 1 illustrated includes a pair of hub members Ill and ll terminating in yokes I2 and I3, respectively.

The hubs l0 and II are adapted to be connected to a driving and driven shaft, respectively, and,

as an example, the hub ill may be connected to the transmission driving shaft and the huh I! may be connected to a shaft extending to the rear axle of the vehicle. Each of the yokes l2 and II has diametrically opposed arms 15 and I6 and the arms of one yoke are disposed between and in spaced relation to the arms of the other yoke.

Now directing attention to Figs. 4 and 5 in particular, each of the arms l5 and It has a ball seating socket or recess l8, which is of spherical contour substantially to the radial center plane of the joint indicated at 20 in Fig. 4. Beyond this plane, and between it and the free end of each arm, the socket is cylindrical in character as indicated at 2|, from which it follows that the first part of the socket is cylindrical and then inwardly thereof the socket is of spherical character, it being understood that the radii of both parts of the socket are the same. It may be noted here that the spherical part I8 is of semi-spherical character and that. the center of the spherical.

surface lies in theplane 20,

Directing attention particularly to Fig. 5, it will be observed that the socket is outwardly closed androllers as'seen in transand 2, the universal joint ameter of the socket so that a ball will be retained against inward movement.

Each of the sockets in the yoke arms receives a ball member 26, which comprises two frustospherical parts 21 and, best shown by Fig. 6. The spherical part 21 has a diametrical bore 29 extending entirely therethrough while the spherical part 28 has a portion 30 projectingslightly into the outer end of the bore 29 and fitting closely therein. The parts 21 and 28 may be held together by having the portion 30 press fitted in the bore 29 sufllciently tight to seal the bore against leakage of lubricant. When so press fitted together, there is no danger of separation of such par-ts after assembly of the joint because the pressure of the cap 50 and socket ll tends to hold the parts together and during operation of the joint, vibration or other causes cannot separate them. Under certain conditions it might be found desirable to fasten the parts 28 and 21 together by brazing or the like.

A cross 35 having four trunnions. each indicated at 36, interconnects the two yokes and the trunnions, respectively, project into the bores 290i the ball members. Roller bearings 31 are disposed around each trunnion I6 and between it and the surface of the bore 29 and-these rollera are substantially as long as the distance between the open inner end of the ball member and theinner base surface of the projecting part Eliot the 'frusto-spherical member 28. Recesses 40 and 4| provided in the frusto-spherical memferrule 69 press fitted on a portion I0 of the trunnion and this ferrule has a wall II which overlaps the spherical surface of the ball member. Sealing is effected by engagement of the sealing ring with the shoulder or base portion of the trunnion and the spherical and edge faces of the ball member and entry of dirt or the like is also prevented by the action of centrifugal force which opposes the movement of foreign matter into the space between the wall H and the ball when the joint is rotating.

Now directing attention to Fig. 6, a modified form of wear ring and sealing arrangement is provided. In this case the wear ring indicated at 15 extends laterally under the inner end of the ball member, while the sealing ring indicated at 1 contacts only the spherical surface of the ball member.

In the construction shown by Fig. 7, a conically formed sealing ring 11 is provided which engages only the spherical surface of the ball member, while the ferrule has a conical wall 18 retaining the sealing ring. The sealing ring in all cases may be composed of felt, cork, or other suitable material.

In connection with the type of joint disclosai, it has been intimated previously that the size of the joint may be reduced and that various factors govern reduction in overall diameter of the joint. In the first place, by using self aligning ball members, the balls may turn in such manner that the bores thereof will be aligned ber II and the trunnions provide a reservoir for the bearing and particularly between the rollers. The member serves as a thrust bearing member for engaging and centering the trunnion and """=c'ross and itwill be observed that the outer parts of bothmembers 28 and 2] contact with =jthe 'outer" spherical parts of the socket II and I thusoutwardimovement of the ball members axially of the trunnions is prevented.

Each ball member is retained within its socket I 8 by'a cap 5! having a spherical portion II enfgagin ithe' ball member. Screws or bolts 52 and fl extending through flanges 54' and 55 on the side edge'sof the cap and-threaded into the arm at"'oppo'site sides of the ball-receiving socket, serveto'securethe cap tothe arm.

' Each of the trunnions liasa shoulder or base portion Gil joining the trunnion surface proper by. means of a. rounded comer SI and between the ends. oi' therollers 31 and such shoulder a relatively hard metal wear ring 62 is located. This wear ring prevents the rollers from moving inwardlyandengagin'g the rounded corner]! and thus allowsrounding of the comer to obtain strength stems; while still preventing engagement of thendsof the rollers with the rounded corner." Ifhislengagement, if not prevented, would probably causethe .rollers'to bendfflex, andskew'. Furthermore, the wear ring 62 preventsthe rollers from digging into the metal of the cross. V

The space between the inner ends of the ball members and the base of the trunnion is sealed by means of a packing ring 66 which engages a part of the. spherical surface on the ball member as indicated at 6'3 and also the end edge face of the ball member as indicated at 68. The

sealing ring is retained in position by means of a lubricant and lubricantis distributed throughout perfectly with the cross and rollers under varying torque conditions. During torque application any trunnion will bend or flex and, although this is not noticeable to the eye, any slight flexing or bending of the trunnion will tend to'cause the torque load to be localized on the outer ends -of the rollers at one circumferential side of the trunnion. and the inner ends of the rollers at the opposite circumferential side. It may be added also that a slight clearance or bearing tolerance is normally present around the rollers and that initial torque application will cause the trunnion to turn circumferentially of the Joint axis a slight amount relative to the ball and 1 this slight relative movement will initially lorollers.

calize load application at the outer ends of the In the present case, however, the ball can turn in a manner which will permit its bore to stay aligned with the trunnion and roller so that the rollers will have full bearing engagement with the trunnion and bore surfaces at all times regardless of the torque load. This being true, smaller rollers may be used for the simple reason ,that joints without the alignment feature have to employ larger rollers in order to take care of the localized pressure condition mentioned during bending or flexing of the trunnions. It follows then in the present case, that the rollers and trunnions may be made shorter, the balls may be disposed closer to the axis of the Joint, the yoke arms may be disposed closer to the axis of the joint and, therefore, that the overall diameter of the Joint may be smaller, the parts individually smaller in dimensions, and that the weight and size may be reduced.

Additive to the foregoing, rollers of smaller diameter may be used, the diameter of the trunnions may be increased, and thus a stronger trunnion actually smaller in overall diameter,

may be used. Again, by eliminating or substantrunnion and cross junction may be obtained while still preventing damage to the rollers. Moreover, this construction and arrangement permits to some extent reduction in trunnion length and overall' diameter of cross and joint.

It has been stated heretofore that the socket portion 18 is semi-spherical andextends to the radial plane of the trunnion axis and that outwardly of this trunnion axis plane, the socket portion 2| is cylindrical. When torque loads are applied through the trunnions and ball members,

each ball'member naturally tends to leave its a If the balls would be exerting more and more pressure against the caps until failure occurred. By having the cylindrical portion 2|, the ball, upon leaving the seat l8 a slight amount forms a surface contact with the cylindrical portion 2| along the radial plane of the trunnion axis and symmetrical thereto and thus a fulcrum for promoting 1 forces against the cap is avoided. Any tendency -of the balls to work farther out of the recesses is thus prevented and the caps are not subjected to damaging forces or damaging deformation. It is to be observed, also, that the outer parts of l the sockets hold the balls against outward'movement along the trunnion axis and this is true in both the cylindrical and spherical parts of the sockets. It may be observed here that the spherical socket prevents outward movement of the ball along the trunnion axis while the ball is seated therein but if the ball moves slightly out of the socket towards the cap, the ball then is held against outward movement along the trunnion axis by the cylindrical part 2|. Thus, the cylindrical portion is important in preventing movement of the ball towards the cap and outwardly along the trunnion axis.

The bridge 23 strengthens each arm and, in

, conjunction with the cap, forms an outwardly closed receptacle so that the only place where water or other foreign matter can get to the ball is through the sealing means and the latter prevents entry at this point. Thus, a closedv ball receiving recess is provided.

Making the ball in two parts is. advantageous since the bore 29 may be formed in part 21 and without interference before the part 28 is added and it is unnecessary to have a relief groove such as would be necessary if the bore were formed in a solid ball. With given ball size and wall thickness thereof, a longer roller contacting surface may thus be provided and actually the net result is that a smaller ball and smaller rollers may be employed while still obtaining desired bearing surface and contact. Thus, this structure is anwill be apparent to those skilled in theart that various modifications may be made without departing from the scope of the appended claims.

What is claimed is:

r 1. In a universal joint of the four trunnion type, including a pair of yokes each having a.

pair of arms, each arm having a recess of substantially cylindrical surface 5 character extending from its free end and terminating inwardly in a bottom surface adapted toengagea ball, that face of the arm next to the joint axis having a slot which opens tothel recess s cross having trunnions respectively projecting through the slots and into the recesses, a ball member on each trunnion and seated in its respective recess and being of substantially the same diameter as the cylindrical surface part ofthe recess and having a diametrically extending openingreceiving the trunnion,small cylindrical-rollers in the ball opening andaroundthe trlmnion, means on the ball substantially engaging the trunnion for centering the cross relative tothe joint axis; each recess embracing the ball .outwardlyibeyond the recessaxis to center the ball with-respect to the joint axis and further being of suchadeptl'rithat a substantial cylindrical surface lpfll't thereof is located between the trunnion axis and th'e'dree end of the arm when the ball is: seated "against.

said bottom surface and which part'is adapted to provide a torque driving ball seat andf-ball centeringmeans, and a cap releasably fastened on the free end of the arm and contacting the ball.

2. In a universal joint of the four trunnion type including a pair of yokes each having a pair of arms, each arm having a recess of subtom surface adapted to engage a ball, that face 7 of the arm next to the joint axis having a slot which opens to the recess, a cross having trunnions respectively projecting through the slots and into the recesses,.a ball member on each trunnion and seated in its respective recess and being of .substantially the same'diameter as the cylindrical surface part of the recess and having a diametrically extending opening receiving the trunnion, small cylindrical rollers in the ball opening and around the trunnion, means on the ball substantially engaging the trunnion for centering the cross relative to the joint axis each recess embracing theball outwardly beyond the recess axis to center the ball with respect to the joint axis and-further being of such depth that a substantial "cylindrical surface part thereof is located between the trunnion axis and the free end of the arm when the ball is seated against said bottom surface, and a cap releasably fastened on.the free end of the arm and contacting the ball, each recess and cap forming a closed receptacle for the ball outwardly of the center of the latter. 1

3. In a universal joint of the four trunnion type, a trunnion bearing'assembly comprising a member'having a recess of substantially cylindrical surface character extending longitudinally of the joint axis and which is open at one end and which terminates in a bottom surface adapted to engage a ball, that side of the member next to the joint axis having a slot which opens to the recess, a trunnion projecting through the slot and the recess, a ball member of substantia ythe same diameter as the .recess and disposed therein in contact with said bottom surface and having an opening receiving the trunnion, small cylindrical rollers in the ball opening and around the trunnion, each recess being of such depth that a substantial cylindrical surface part thereof is located between the trunnion axis and the open end of the recess when the ball is seated against said bottom surface, and a second member releasably fastened on the first member over the open end of the recess and in contact with the ball.

4. In a universal joint 01' the four trunnion type, including a pair of yokes each having a pair of arms, each arm having a recess extending from its free end longitudinally of the joint axis and terminating in a bottom surface adapted to engage a ball, that face of the arm next to the joint axis having a slot which opens to the recess, a cross having trunnions respectively projecting through the slots and into the recesses, a ball member on each trunnion and disposed in its respective recess in contact with said bottom surface and being of substantially the same diameter as the width of the recess and having a diametrically extending opening receiving the trunnion, small cylindrical rollers in the ball opening and around the trunnion, means on the ball substantially engaging the trunnion for centering the cross relative to the joint axis, eachrecess embracing the ball outwardly of the joint axis to center the ball with respect to the joint axis and each recess being of such depth that a substantial part thereof is located between the trunnion axis and the free end of the arm when the ball is initially seated against said bottom surface and which part is adapted to provide a side torque driving ball seat, and a cap releasably fastened on the free end of the arm and contacting the ball. a

5. In a universal joint of the four trunnion type, a trunnion bearing assembly comprising a member having a recess extending longitudinally of the joint axis and terminating at one end in a ball engaging surface adapted to engage a ball, that side of the member next to the joint axis having a slot which opens to the recess, a trunnion projecting through the slot and into the recess, a ball member on the trunnion and disposed in the recess in contact with said bottom surface and being of substantially the same diameter as the width of the recess and having a diametrically extending opening receiving the trunnion, each recess being of such depth that a substantial part thereof is located between the trunnion axis and the other end of the recess when the ball is initially seated against said ball engaging surface to provide a torque driving ball seat, and a member on the first member over said other end of the recess and in contact with the ball, one of said members having operative engagement with said ball outwardly of its center, to center the ball with respect to the joint axis.

GEORGE E. DUNN. 

